Pre-positionable prosthetic hand

Abstract

The present invention is directed to a pre-positionable prosthetic hand, including one or more pre-positionable joints. Pre-positionable joints in accordance with embodiments of the present invention include a multi-axial thumb joint, a metacarpal-phalangeal joint and a wrist joint. Additionally, the present invention may include a number of pre-positionable phalanges or fingers having a segmented construction, which allows them to be placed in various positions. The present invention may be used in connection with a pentadactyl glove and may be positioned in such griping positions as: a key or lateral grip, a hook grip, a cylindrical grip, a spherical grip and a tip-pinch grip.

1 . A pre-positionable prosthetic hand, comprising:
 a palm plate; and   a thumb interconnected to the palm plate through an attachment member, the attachment member being attached to the thumb at a base of the thumb, wherein the thumb is slidably moveable along the attachment member, and wherein the thumb is rotatable about the attachment member.   
   
   
       2 . The prosthetic hand of  claim 1 , further comprising:
 a phalangeal section rotatably attached to the palm plate, wherein the phalangeal section is selectively postionable in a plurality of discrete positions between −90 degrees and +90 degrees with respect to a plane defined by the palm plate.   
   
   
       3 . The prosthetic hand of  claim 1 , further comprising:
 a wrist joint providing a movable connection between the palm plate and a base member, the base member being rigidly connected to a bead, wherein an end point of the palm plate is rotatable around the bead.   
   
   
       4 . The prosthetic hand of  claim 1 , further comprising:
 a thumb biasing member connected to the palm plate and to the thumb, the thumb biasing member being operable to urge the thumb in at least one of an open position and a closed position.   
   
   
       5 . The prosthetic hand of  claim 1 , wherein the attachment member includes a U-bolt and the base of the thumb includes a U-bolt hole, wherein the U-bolt is received through the U-bolt hole and attached to the palm plate at both ends of the U-bolt. 
   
   
       6 . The prosthetic hand of  claim 4 , wherein the thumb biasing member includes a spring disposed on the dorsal side of the hand, a first end of the spring being attached to palm plate, and a second end of the spring being attached to a cord, the cord being disposed through a cord hole in the palm plate and attached to the thumb. 
   
   
       7 . The prosthetic hand of  claim 6 , wherein the thumb includes a bushing moveable within a bushing track, the bushing being attached to the cord, wherein with the bushing at a first end of the bushing track, the thumb is disposed in the closed position, and with the bushing at a second end of the bushing track, the thumb is disposed in the open position. 
   
   
       8 . The prosthetic hand of  claim 7 , wherein the bushing track includes an arcuate shape having a neutral-bias point, wherein with the bushing between the neutral-bias point and the first end of the bushing track, the thumb biasing member urges the thumb towards the closed position, and with the bushing between the neutral-bias point and the second end of the bushing track, the thumb biasing member urges the thumb towards the open position. 
   
   
       9 . The prosthetic hand of  claim 8 , wherein the neutral bias point is located closer to the second end of the bushing track than the first end of the bushing track. 
   
   
       10 . The prosthetic hand of  claim 8 , wherein the neutral bias point is located at substantially the center of the bushing track. 
   
   
       11 . The prosthetic hand of  claim 1 , wherein the thumb includes an angled tip. 
   
   
       12 . The prosthetic hand of  claim 2 , wherein the phalangeal section includes an axle having a rotatable connection to the palm plate, the first end of the axle being connected to the phalangeal section at a first mounting point, the second end of the axle being connected to the phalangeal section at a second mounting point, the first and second mounting points allowing translational movement of the axle between a locked position and an unlocked position. 
   
   
       13 . The prosthetic hand of  claim 12 , wherein an axle spring urges the axle towards the locked position, wherein with the axle in the locked position the phalangeal section is locked in one of the plurality of discrete positions, wherein a user may urge the axle into an unlocked position by pressing on an end of the axle, and wherein with the axle in the unlocked position the phalangeal section may freely rotate. 
   
   
       14 . The prosthetic hand of  claim 13 , wherein the second end of the axle includes an enlarged portion operable to engage the second mounting point to provide the plurality of discrete positions of the phalangeal section of the hand. 
   
   
       15 . The prosthetic hand of  claim 3 , wherein the wrist joint includes a wrist core provided in association with a wrist cup, the wrist core being rigidly attached to the palm plate and having the endpoint rotatable around the bead, the wrist cup having a curved inner surface operable to engage a rim portion of the wrist core, wherein movement of the rim of the wrist core along the inner surface of the wrist cup defines a range of motion for the palm plate around the bead. 
   
   
       16 . A method of using a prepositionable prosthetic hand, comprising:
 moving a thumb along an attachment member, wherein the attachment member interconnects the thumb to a palm plate; and   rotating the thumb about the attachment member, wherein rotational movement of the thumb is biased towards at least one of an open position and a closed position.   
   
   
       17 . The method of  claim 16 , further comprising:
 moving a phalangeal section into one of a plurality of locked positions, wherein each locked position includes the phalangeal section disposed at a different angle with respect to the palm plate.   
   
   
       18 . The method of  claim 17 , further comprising:
 moving the palm plate into an angled position with respect to a base member of the prepositionable hand.   
   
   
       19 . The method of  claim 18 , further comprising:
 moving at least one phalange associated with the prepositionable hand into a bent position.   
   
   
       20 . The method of  claim 17 , wherein the prepositionable hand is moved into at least one the following positions:
 a lateral grip, wherein the thumb is disposed in a closed pronated position and the phalangeal section is disposed at about a 60 degree angle with respect to the palm plate;   a hook grip, wherein the thumb is disposed in a closed pronated position and the phalangeal section is disposed at about a 90 degree angle with respect to the palm plate;   a cylindrical grip, wherein the thumb is disposed in an open neutral position and the phalangeal section is disposed at about a 0 degree angle with respect to the palm plate;   a spherical grip, wherein the thumb is disposed in an open semi-pronated position and the phalangeal section is disposed at about a 30 degree angle with respect to the palm plate; and   a spherical grip, wherein the thumb is disposed in an open neutral position and the phalangeal section is disposed at about a 30 degree angle with respect to the palm plate.   
   
   
       21 . A pre-positionable artificial human hand, comprising:
 a thumb;   means for positioning the thumb in a lateral position along an attachment member and in a rotated position around said attachment member; and   means for biasing the thumb in at least one of an open position and a closed position, wherein the open and closed positions are established at rotated positions of the thumb.   
   
   
       22 . The prepositionable hand of  claim 21 , further comprising:
 a phalangeal section;   means for adjusting the phalangeal section at a plurality of locked positions, wherein each locked position includes the phalangeal section disposed at different angles with respect to a palm plate that is connected to the means for positioning.   
   
   
       23 . The prepositionable hand of  claim 22 , further comprising:
 a base member;   means for positioning the palm at angle with respect to the base member.   
   
   
       24 . A pre-positionable prosthetic hand, comprising:
 a palm plate;   a thumb interconnected to the palm plate through an attachment member, the attachment member being attached to the thumb at a base of the thumb, wherein the thumb is slidably moveable along the attachment member, and wherein the thumb is rotatable about the attachment member;   a phalangeal section rotatably attached to the palm plate, wherein the phalangeal section is selectively postionable in a plurality of discrete positions between −90 degrees and +90 degrees with respect to a plane defined by the palm plate;   a wrist joint providing a movable connection between the palm plate and a base member, the base member being rigidly connected to a bead, wherein an end point of the palm plate is rotatable around the bead;   a thumb biasing member connected to the palm plate and to the thumb, the thumb biasing member being operable to urge the thumb in at least one of an open position and a closed position;   wherein the attachment member includes a U-bolt and the base of the thumb includes a U-bolt hole, wherein the U-bolt is received through the U-bolt hole and attached to the palm plate at both ends of the U-bolt;   wherein the thumb biasing member includes a spring disposed on the dorsal side of the hand, a first end of the spring being attached to palm plate, and a second end of the spring being attached to a cord, the cord being disposed through a cord hole in the palm plate and attached to the thumb;   wherein the thumb includes a bushing moveable within a bushing track, the bushing being attached to the cord, wherein with the bushing at a first end of the bushing track, the thumb is disposed in the closed position, and with the bushing at a second end of the bushing track, the thumb is disposed in the open position;   wherein the bushing track includes an arcuate shape having a neutral-bias point, wherein with the bushing between the neutral-bias point and the first end of the bushing track, the thumb biasing member urges the thumb towards the closed position, and with the bushing between the neutral-bias point and the second end of the bushing track, the thumb biasing member urges the thumb towards the open position;   wherein the neutral bias point is located closer to the second end of the bushing track than the first end of the bushing track;   wherein the neutral bias point is located at substantially the center of the bushing track;   wherein the thumb includes an angled tip;   wherein the phalangeal section includes an axle having a rotatable connection to the palm plate, the first end of the axle being connected to the phalangeal section at a first mounting point, the second end of the axle being connected to the phalangeal section at a second mounting point, the first and second mounting points allowing translational movement of the axle between a locked position and an unlocked position;   wherein an axle spring urges the axle towards the locked position, wherein with the axle in the locked position the phalangeal section is locked in one of the plurality of discrete positions, wherein a user may urge the axle into an unlocked position by pressing on an end of the axle, and wherein with the axle in the unlocked position the phalangeal section may freely rotate;   wherein the second end of the axle includes an enlarged portion operable to engage the second mounting point to provide the plurality of discrete positions of the phalangeal section of the hand;   wherein the wrist joint includes a wrist core provided in association with a wrist cup, the wrist core being rigidly attached to the palm plate and having the endpoint rotatable around the bead, the wrist cup having a curved inner surface operable to engage a rim portion of the wrist core, wherein movement of the rim of the wrist core along the inner surface of the wrist cup defines a range of motion for the palm plate around the bead.